TY - JOUR
T1 - The genetic and environmental architecture to the stability of IQ
T2 - Results from two independent samples of kinship pairs
AU - Beaver, Kevin M.
AU - Schwartz, Joseph A.
AU - Connolly, Eric J.
AU - Nedelec, Joseph L.
AU - Al-Ghamdi, Mohammed Said
AU - Kobeisy, Ahmed Nezar
N1 - Funding Information:
This research uses data from the Modernization and Enhancement of the Collaborative Perinatal Project conducted by J.P. Lawlor, E. Gladen, D. Dhavale, D. Tamagoglu, J.B. Hardy, A.K. Duggan, W.W. Eaton, and E.F. Torrey. “Modernization and Enhancement of the Collaborative Perinatal Project (1959–74)”, The Johns Hopkins University 2005. Data can be found at ftp://sph-ftp.jhsph.edu/cpp . The project was funded by the Stanley Medical Research Institute, Bethesda MD and NIMH grant 070333 . No direct support was received from these sources for this analysis.
Funding Information:
This research uses data from Add Health, a program project designed by J. Richard Udry, Peter S. Bearman, and Kathleen Mullan Harris, and funded by a grant P01-HD31921 from the Eunice Kennedy Shriver National Institute of Child Health and Human Development , with cooperative funding from 17 other agencies. Special acknowledgment is due to Ronald R. Rindfuss and Barbara Entwisle for assistance in the original design. Persons interested in obtaining data files from Add Health should contact Add Health, Carolina Population Center, 123 W. Franklin Street, Chapel Hill, NC 27516-2524 ( [email protected] ). No direct support was received from grant P01-HD31921 for this analysis.
PY - 2013/9
Y1 - 2013/9
N2 - Existing research has revealed that IQ remains relatively stable over the life course, though questions remain about how stable IQ is and whether the stability of IQ varies across different developmental periods of the life course. Despite this stability, there are also questions surrounding the factors that might explain the stability of IQ. Against this backdrop, we conduct bivariate genetic models to estimate genetic, shared environmental, and nonshared environmental influences on the stability of IQ. To do so, we analyze kinship pairs drawn from two separate longitudinal samples: The National Collaborative Perinatal Project (CPP) and the National Longitudinal Study of Adolescent Health (Add Health). Across both samples, IQ was found to be relatively stable. Moreover, the genetic analyses revealed that between 66% and 83% of the stability in IQ was due to genetic factors and between 43% and 69% of the change in IQ was due to genetic factors. The remainder of the stability and change in IQ was the result of a combination of shared and nonshared environmental influences. Importantly, some substantive race differences emerged in respect to genetic and environmental influences on the stability of IQ. We conclude with a discussion of the limitations of the study and avenues for future research.
AB - Existing research has revealed that IQ remains relatively stable over the life course, though questions remain about how stable IQ is and whether the stability of IQ varies across different developmental periods of the life course. Despite this stability, there are also questions surrounding the factors that might explain the stability of IQ. Against this backdrop, we conduct bivariate genetic models to estimate genetic, shared environmental, and nonshared environmental influences on the stability of IQ. To do so, we analyze kinship pairs drawn from two separate longitudinal samples: The National Collaborative Perinatal Project (CPP) and the National Longitudinal Study of Adolescent Health (Add Health). Across both samples, IQ was found to be relatively stable. Moreover, the genetic analyses revealed that between 66% and 83% of the stability in IQ was due to genetic factors and between 43% and 69% of the change in IQ was due to genetic factors. The remainder of the stability and change in IQ was the result of a combination of shared and nonshared environmental influences. Importantly, some substantive race differences emerged in respect to genetic and environmental influences on the stability of IQ. We conclude with a discussion of the limitations of the study and avenues for future research.
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U2 - 10.1016/j.intell.2013.06.012
DO - 10.1016/j.intell.2013.06.012
M3 - Article
AN - SCOPUS:84880362117
SN - 0160-2896
VL - 41
SP - 428
EP - 438
JO - Intelligence
JF - Intelligence
IS - 5
ER -